A charging device of this type designed as a charging stock preheater is known, for example, from JP 7-180975 A.
In charging devices of this type, problems arise when, during the charging of steel scrap, charging stock of widely varying size, such as in the form of chips, railway rails, engine blocks, etc, are to be heated in the charging stock preheater without being sorted first and then conveyed in batches to the discharge opening and charged into a melting vessel. The pusher, which is rigidly moved back and forth by a linear drive, easily becomes jammed by smaller pieces of scrap. In addition, when the pusher is pushed forward from the retracted position, which exposes the shaft floor, toward the discharge opening, and especially when the pusher is not formed too planar, bulky pieces of charging stock are pressed against the upper edge of the discharge opening of the shaft, where they then interfere with the transport process. In the known charging stock preheater, the susceptibility to malfunction during material transport is certainly reduced somewhat in that blocking elements are provided on two levels, by means of which the column of charging stock can be divided into smaller amounts and then discharged. Blocking elements of this type, however, are cumbersome and are also vulnerable to impact loads during the introduction of heavy scrap into the charging stock preheater.